Small white polyps?

[OlPainless]

Just started seeing these show up in mass today. In my filter and in the crevices of the rock in the tank. What are these and what to do?

 

[tbrown]

Look like pineapple sponges.

 

[DinoMagnet]

+1 pineapple sponge since the places you said tend to be dark with little to no light.

 

[lxxnp1234]

+1 pineapple sponge

 

[OlPainless]

Thanks everyone, seems that they are fairly harmless and have some benefit to filtering. Just got concerned when I first saw how many there were. Win for the R2R community!